Problem complex SUMPRODUCT formula

Hello

Someone gave me this formula a while ago, calculating the mean temperature between two times. But I also want the standard deviation now, and I just can't understand the first formula anyway...

=IFERROR(SUMPRODUCT(--($F$2:$F$5555>=A2),--($F$2:$F$5555<=B2),($G$2:$G$5555))/SUMPRODUCT(--($F$2:$F$5555>=A2),--($F$2:$F$5555<=B2)),"none in range")

Help please!

Al



more details= Basically, I recorded the temperature every 10 seconds (columns F&G), and now I want for each row of my dataset the average temperature between the time in column A and the one in B. I get that with the formula already, but not the standard deviation...